Commit 77fb33cb authored by Ankit Nautiyal's avatar Ankit Nautiyal
Browse files

drm/i915/psr: Add helper to get min psr guardband 



Introduce a helper to compute the max link wake latency when using
Auxless/Aux wake mechanism for PSR/Panel Replay/LOBF features.

This will be used to compute the minimum guardband so that the link wake
latencies are accounted and these features work smoothly for higher
refresh rate panels.

v2:
- Account for flag `req_psr2_sdp_prior_scanline` and scl lines while
  computing min guardband. (Jouni)
- Use wake lines only for eDP with panel_replay and sel_update flags
  set. (Jouni)

Bspec: 70151, 71477
Signed-off-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: default avatarJouni Högander <jouni.hogander@intel.com>
Link: https://lore.kernel.org/r/20251017123504.2247954-2-ankit.k.nautiyal@intel.com
parent c390bf07

drivers/gpu/drm/i915/display/intel_psr.c

+27 −0
Original line number Diff line number Diff line
@@ -4499,3 +4499,30 @@ void intel_psr_compute_config_late(struct intel_dp *intel_dp, 


	intel_psr_set_non_psr_pipes(intel_dp, crtc_state);

}



int intel_psr_min_guardband(struct intel_crtc_state *crtc_state)

{

	struct intel_display *display = to_intel_display(crtc_state);

	int psr_min_guardband;

	int wake_lines;



	if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP))

		return 0;



	if (crtc_state->has_panel_replay)

		wake_lines = crtc_state->alpm_state.aux_less_wake_lines;

	else if (crtc_state->has_sel_update)

		wake_lines = DISPLAY_VER(display) < 20 ?

			     psr2_block_count_lines(crtc_state->alpm_state.io_wake_lines,

						    crtc_state->alpm_state.fast_wake_lines) :

			     crtc_state->alpm_state.io_wake_lines;

	else

		return 0;



	psr_min_guardband = wake_lines + crtc_state->set_context_latency;



	if (crtc_state->req_psr2_sdp_prior_scanline)

		psr_min_guardband++;



	return psr_min_guardband;

}

drivers/gpu/drm/i915/display/intel_psr.h

+1 −0
Original line number Diff line number Diff line
@@ -85,5 +85,6 @@ bool intel_psr_needs_alpm_aux_less(struct intel_dp *intel_dp, 
				   const struct intel_crtc_state *crtc_state);

void intel_psr_compute_config_late(struct intel_dp *intel_dp,

				   struct intel_crtc_state *crtc_state);

int intel_psr_min_guardband(struct intel_crtc_state *crtc_state);



#endif /* __INTEL_PSR_H__ */